What component is responsible for dynamics ?

Unsound I must say that has`nt been the case for me, but to each their own. What ever works best then go for it.

Watts are cheap, high powered SS amps with medium efficiency full range speakers can produce impressive dynamics.

High efficiency speakers will raise the noise floor, same with cheap tube equipment.

Without a very large enclosure, high efficiency speakers will lack low end due to Hoffman's Iron Law.

Bookshelf or limited LF speakers lack the necessary low end impact needed.

Yes, Unsound, your last post doesn't make alot of sense to me, either. High efficiency speakers, especially horns but also other types, are well known for very high quality at the very softest dynamics. This is one huge reason why so many professionals prefer them. I have never found noise floor to be higher in high efficiency speakers, quite the opposite in fact.

One of the fundamental advantages of high efficiency is it allows low level detail and microdynamic ebb and flow to be appreciated at low and modest listening levels.
There is less need to"crank it up" in order for the sound to come "alive".

This is why the higher the efficieny becomes the need for a quiet well built amp with a very low noise floor is required. These types of speaker will reveal any noise, even at quite low sound levels. The advantage is uncovering more of music`s nuance and subtle -micro inflections.

Hi Face,
My believe as always been do what works best for you and meets your objectives,Having had much experience and exposure to both approaches, personally the high efficient speaker with lower power amplifier has been much more realistic and satisfying(not really close).

But that`s me, your experiences are different and I can certainly appreciate that. What ever road gets you there, follow it.
Best Regards,